''De Furtivis Literarum Notis'' (''On the Secret Symbols of Letters'') is a 1563 book on
cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...
written by
Giambattista della Porta
Giambattista della Porta (; 1535 – 4 February 1615), also known as Giovanni Battista Della Porta, was an Italian scholar, polymath and playwright who lived in Naples at the time of the Renaissance, Scientific Revolution and Reformation.
Giamba ...
.
The book includes three sets of cypher discs for coding and decoding messages and a
substitution cipher
In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with the help of a key; the "units" may be single letters (the most common), pairs of letters, trip ...
improving on the work of
Al-Qalqashandi
Shihāb al-Dīn Abū 'l-Abbās Aḥmad ibn ‘Alī ibn Aḥmad ‘Abd Allāh al-Fazārī al-Shāfiʿī better known by the epithet al-Qalqashandī ( ar, شهاب الدين أحمد بن علي بن أحمد القلقشندي; 1355 or 1356 &ndash ...
.
References
{{reflist
1563 books
Cryptography books
Non-fiction books